The automation of machinery for mass production and for “old economy” industrial functions is very well known. Shock absorbers and accelerators are needed in many settings where machine parts move repeatedly in a reciprocating or other repeated motion.
Various industrial shock absorbers and acceleration devices are known in the art. For example, standard shock absorbers employ a liquid such as a special oil being forced through a comparatively small orifice to progressively diminish the force being absorbed The primary drawback of such hydraulic shock absorbers is the fact that significant heat dissipation results when the oil is forced through the orifice and the kinetic energy of the piston is brought to zero. The kinetic energy is transformed into heat energy. As a result, the system loses the ability to re-use that energy that has been transformed into heat. Also, the possibility of system overheating greatly reduces the applicability of these shock absorbers at high frequencies. On the other hand, the advantage of using oil-based hydraulic shock absorbers is that they are very powerful since oil is virtually non-compressible. With use of oil-based shock absorbers, a uniform force can be maintained throughout the stroke. Since work is proportional to force and distance, this maximizes the power of the shock absorber.
Another standard type of industrial shock absorber is pneumatic, wherein air or another gas is forced through a small orifice. This avoids the disadvantage of oil-based hydraulic shock absorbers because there is significantly less heat dissipation from air than oil. This does not provide a very powerful type of shock absorber since air is compressible and hence the force maintained through the stroke decreases more and more as the stroke progresses.
Air can also be used differently as when the air acts as a spring. The disadvantage of an air spring is that there is likely to be a strong return force or bounce-back effect unless a lock or other separate mechanism is employed to hold the spring in place at the end of the retraction stroke. The lock would also have to be controlled by an electric or other mechanism that releases the lock when desired. Any such separate mechanism of a lock and control structure adds significantly to the expense and complexity of the device. Even with the lock and control mechanism, the device still is saddled with a meaningful return force.
Shock absorbing effect can also be achieved by using a helical or other mechanical spring. But for a helical spring to be powerful it would have to be very large and then the lock would have to be large and a special release mechanism for the lock would be required. All that adds to the expense and complexity of the device. Moreover, the force applied by a helical spring is not uniform and decreases as the stroke unfolds which reduces the amount of absorbed energy. More energy could be absorbed by a shock absorber that has a uniform force throughout the stroke. A lot more energy can be stored with air than with a helical spring in the same given amount of space. Finally, all shock absorbers with locks, for example springs, are not sufficiently safe because there always exists the danger than the lock or other mechanism for holding the spring in the compressed state will fail.
Another problem in shock absorbers is maintaining a sufficiently low return force. If the return force is too great then equipment may be damaged and energy is wasted. Accordingly, depending upon the size of the shock absorber, there is a maximum acceptable return force for that shock absorber.
A shock absorber that is powerful although not quite as powerful as oil-based shock absorbers, is safe, significantly less expensive to use in that it saves a lot of energy, has a low return force and does not incur significant heat dissipation would represent a significant advance in the art. In particular, industrial shock absorber that are suitable for high cycling frequency applications with low or medium inch-pounds per cycle but with high inch-pounds per hour could benefit greatly from a shock absorber that has the above characteristics.
If such a shock absorber were also able to function as an acceleration device, it would be remarkably valuable. In general, industrial equipment not only use shock absorbers to absorb the energy during the retraction stroke but also employ a separate accelerator or actuator to move the machine part in the reverse direction. This use of separate equipment is expensive. A large cost savings could be achieved if a single device could be employed as both a shock absorber and as an accelerator. Tremendous energy savings could be achieved by recycling energy used during the shock absorption and re-used for acceleration, much lower propelling force would be needed, a lower return force could be achieved, heavier weight could be moved at high cycling frequency and a higher cycling frequency could be achieved. The present invention achieves these and many other advantages.